1. Field of Invention
The present invention relates to an electronic ballast device. More particularly, the present invention relates to an electronic lamp ballast device.
2. Description of Related Art
Compared with the incandescent light bulb, the advantages of the fluorescent lamp are the higher luminous efficacy, the longer life and the lower heat. Therefore, the fluorescent lamp replaces the incandescent light bulb quickly, and becomes the mainstream.
Generally speaking, the fluorescent lamp has no filament running through it. Instead, cathodes at each end send current through mercury vapors sealed in the tube. Ultraviolet radiation is produced as electrons from the cathodes knock mercury electrons out of their natural orbit. Some of the displaced electrons settle back into orbit, throwing off the excess energy absorbed in the collision. Almost all of this energy is in the form of ultraviolet radiation. To turn this radiation into visible light, the inside of the tube has a phosphor lining. The phosphors have the unique ability to lengthen UV wavelengths to a visible portion of the spectrum. As a result, the phosphors are excited to fluorescence by bursts of UV energy. Fluorescent lamps require a sweep frequency circuit to preheat the lamp, extending the lifetime of the lamp.
Nevertheless, the conventional sweep frequency circuit for preheating is too complex, and the capacitance in the circuit takes too much time to be charged or release the stored charges. Consequently, how to modify and improve the sweep frequency circuit so as to decrease the cost and maintain the preheating function becomes a significant issue.